Battling low chlorine levels all summer

[hensler74]

So in about 4 hours I will be 72 hours into my SLAM. On Sunday and today I have been adding LC to keep me at SLAM level about every hour, yesterday was hard because I was at the office and only added LC in the morning and then every hour when I got home. I have been brushing once a day and vacuuming as needed. I am no longer noticing the slight algae growth on the walls in the shallow end and of course the pool is still crystal clear.
I did an OCLT last night but my FC was 21.5 at 8:56 pm on 7/31 and at 6:36 am today it was 16.5 so lots of loss. Can that be expected since the levels are so high? Should I run an OCLT tonight after adding LC around 7:30 pm and then wait till sundown which is around 8:28 today. Us that FC as my point and then see if I have a large loss again at sunrise? My CC was 0.5 on 7/29 before starting the SLAM and I have checked it again on 7/31 and it was 0.0 and then again this morning and it was 0.0.

Would I be ok doing another OCLT tonight but letting the chlorine level fall to a lower level to see if I still have a loss?

 

[Rancho Cost-a-Lotta]

I did an OCLT last night but my FC was 21.5 at 8:56 pm on 7/31 and at 6:36 am today it was 16.5 so lots of loss. Can that be expected since the levels are so high?

I agree that's still a significant loss (down 23% overnight). When testing at higher levels, there is an increased margin of error. This is where consistent and accurate testing methods are critical. Make sure sample size and drop size are the same for each test. I would not lower FC to the complete the OCLT. You may shoot yourself in the foot.

 

[Rancho Cost-a-Lotta]

...I use a syringe when I need accurate water sample sizing:

 

[hensler74]

I agree that's still a significant loss (down 23% overnight). When testing at higher levels, there is an increased margin of error. This is where consistent and accurate testing methods are critical. Make sure sample size and drop size are the same for each test. I would not lower FC to the complete the OCLT. You may shoot yourself in the foot.

So I am looking to not have any loss at all while doing the SLAM from night to morning? This is where I am confused at the whole process. I usually do my last reading around 9 pm each night and add the recommend LC to get me back to SLAM level and every morning before work take a reading and am always below SLAM level by 3-4 ppm. My readings are listed below if it will help these are only FC readings with recommend LC added after each reading and using 5 mL sample, 1 scoop R-0870 and drops of R-0871 to test. I have been using he 5 mL line that came with the FAS-DPD test kit but guess I will find a syringe as you stated in your other reply and use it.

7/29
7:53 pm - 2.5
9:40 pm 14
7/30
8:09 am - 9
9:11 am - 14
10:14 am - 13
2:09 pm - 14
3:51 pm - 13
4:54 pm - 12
7:54 pm - 14
9:02 pm - 15
7/31
6:38 am - 15
5:15 pm - 7
7:05 pm - 15
8:30 pm - 13
8:52 pm - 21.5
8/1
6:39 am - 16.5
9:07 am - 11
10:17 am - 16
12:18 pm - 13
2:05 pm - 15
3:26 pm - 15
4:51 pm - 15

 

[Rancho Cost-a-Lotta]

What happened the night before. You ended the night at 15 PPM and began the morning with 15 ppm. Are those accurate results?

 

[hensler74]

What happened the night before. You ended the night at 15 PPM and began the morning with 15 ppm. Are those accurate results?

Didn’t take a reading before I went to bed so that 15 was around 9 pm and then I added the recommended LC to raise back to SLAM and went to bed. The only time I have checked it 10-15 minutes after adding LC was last night when I ended with 21.5 ppm.

What happened the night before. You ended the night at 15 PPM and began the morning with 15 ppm. Are those accurate results?

Am I supposed to add the recommended LC and then test not long after adding to confirm I have reached SLAM level? I have not been doing that other than one time and that was last night trying to get a good FC for the OCLT I did which resulted in going from 21.5 to 16.5

 

[Rancho Cost-a-Lotta]

Am I supposed to add the recommended LC and then test not long after adding to confirm I have reached SLAM level?

It's not necessary unless you are doing the OCLT.

 

[hensler74]

It's not necessary unless you are doing the OCLT.

I guess that is what I really meant when I stated let the FC level go down. Should I test around 7:45-8 add the recommended LC and then test again at sunset to get a FC for the OCLT or does the FC reading need to be SLAM level exactly to perform the OCLT

 

[Rancho Cost-a-Lotta]

You want to stay at or above SLAM level, even when doing the OCLT. It's your call whether or not to test before that last dose.

 

[hensler74]

You want to stay at or above SLAM level, even when doing the OCLT. It's your call whether or not to test before that last dose.

Ok. Just tested again using a syringe to measure correct sample size and had to start a new bottle of R-0871 and my FC was 20 which is more than it has read with any samples except one last night 15 minutes after adding LC. Will do a couple more tonight and try to get one at or above SLAM to do a OCLT.
The rest of the week I have to be back in the office so will not be able to tend to it hourly and ever 2 hours.

 

[Rancho Cost-a-Lotta]

Good luck. I hope you pass. It only gets easier after you're done.

 

[hensler74]

UPDATE

Well I didn’t get to do the OCLT Tuesday night like I thought so Ellet the SLAM doing best I could with work yesterday and did the OCLT last night. Still had a 2ppm loss overnight so keeping it going best I could today with work. Only had to add 8 ounces this morning but didn’t get to check again till after 5 pm today and had to add one full gallon. Guess tonight I will check and add until bed and do the same in the morning it have to be in the office again tomorrow so the monitoring will be the same schedule as yesterday and today.

This process is no joke but going to keep it going until I can pass the last test of the OCLT. CC has been going from 0.5 to 0.0 which I believe is ok as long as I don’t go above 0.5.

 

[hensler74]

I do have a question though. How often should I be pulling the main drains and lights to clean them? I have only done it the one time and gave them all a very good scrubbing but the light in the spa I could not get out to clean. Not sure why it won’t come out but we tried everything except brute force cause I didn’t want to break anything and it was just installed in April 2021 which puzzles me on why I cannot get it out.

 

[Rancho Cost-a-Lotta]

A loss of 2 ppm means you're getting close. Much better than Tuesday's OCLT.

One good scrubbing of those areas should be good.

 

[hensler74]

A loss of 2 ppm means you're getting close. Much better than Tuesday's OCLT.

One good scrubbing of those areas should be good.

I figured I was getting close. I need it to end soon as I know this pump running 24/7 is probably putting a strain on that 17 year old pump lol. It only runs this much when we getting what little freezing temps we get here in Texas and I can’t stomach replacing it yet since it still works just fine.
Heading to get more LC to get me through the next few days but luckily I am only going through about 2 gallons a day now if even that.

Thanks again for all your replies and knowledge.

 

[hensler74]

So I was in the pool this morning scrubbing the walls and floor and noticed what I thought was a blade of grass. When I brushed over it the thing did not move. This is the only spot in the pool like this and I scrubbed it like crazy with no luck. Should I be worried about this? I am using a plastic bristle brush to scrub. Should I get a wire brush and scrub it to see if it comes off?

Picture is not the best but you can see it right in front of my big toe.

 

[Rancho Cost-a-Lotta]

It could be organic or it could be rust or ?? Check out the article below for ways to ID the stain:

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

If you use a wire brush in your pool, make sure it's stainless steel. If regular wire brush bristles come loose, they'll leave rust stains.

Whatever it is, it's likely not causing FC loss.

 

[hensler74]

It could be organic or it could be rust or ?? Check out the article below for ways to ID the stain:

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

If you use a wire brush in your pool, make sure it's stainless steel. If regular wire brush bristles come loose, they'll leave rust stains.

Whatever it is, it's likely not causing FC loss.

Thanks for that link. I am thinking inorganic probably since I have been in a SLAM for almost 7 days now.
I would suspect I don’t want to do the trichlor puck test during the SLAM but would it be ok to do any of them for the inorganic during the SLAM or just wait till SLAM is done and test to see.
I believe you are correct that it is probably not causing FC loss.

 

[reggiehammond]

No risk to SLAM to test it now either way. I would guess it's rust as I've seen similar in my own pool.

 

[Rancho Cost-a-Lotta]

I have been in a SLAM for almost 7 days now.

You've got to be close.